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1.
Arch Microbiol ; 204(6): 302, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35524014

RESUMO

Our aim was to explore the microbial community composition (bacteria and fungi) of fermented fish (pla-ra) from Northeast Thailand. We also made functional predictions concerning these microbial communities. The association between the microbiota and odor intensity was also analyzed. Fourteen samples of 1-year fermented fish samples derived from seven local markets in Khon Kaen, Northeast Thailand were used. The microbial community composition of each was investigated by sequencing the V1-V9 regions of the 16S rRNA gene (bacteria) and the ITS gene (fungi) using an Illumina MiSeq platform. Functional prediction analysis was conducted through Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) based on the use of the bacterial 16S rRNA gene sequences. The bacterial communities were rich, comprising 402 genera from 28 phyla, including such genera as Tetragenococcus, Staphylococcus, Virgibacillus, Lactobacillus and Lentibacillus. The fungal communities comprised 7 phyla and 60 genera, such as Heterobasidion, Densospora, Exophiala and Monascus. The bacterial community functional analysis revealed an association with six biological metabolic pathway categories (e.g., metabolism, genetic information processing, environmental information processing, cellular processes, organismal systems and human diseases) with 17 subfunctions, showing the richness of bacterial community functions. Odor-association analysis revealed that Brevibacterium, Brachybacterium and Chromohalobacter were more abundant in the weak-odor group, while Noviherbaspirillum was more abundant in the strong-odor group. This study provides a preliminary analysis of pla-ra microbial community structure and function in popular traditional Thai foods. Functional prediction analysis might be helpful to improve our knowledge of the microbiota in fermented fish.


Assuntos
Micobioma , Animais , Bactérias/genética , Fermentação , Peixes/microbiologia , Fungos/genética , Filogenia , RNA Ribossômico 16S/genética , Tailândia
2.
Sci Rep ; 12(1): 4642, 2022 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-35301363

RESUMO

Some marine fishes are algae-feeding, and the microorganisms in their digestive tracts produce carbohydrate hydrolyzing enzymes such as agarose and fucosidase, which are potentially interesting resource for new functional enzymes. The purpose of this study was to establish a method for identifying and utilizing characteristic bacteria from the intestines of two algae-eating fish species: Andamia tetradactylus, which exclusively eats algae on the rock surface, and stellar rockskipper Entomacrodus stellifer, which feeds on both algae and invertebrates. We tested the species composition of the intestinal bacterial flora and found that Proteobacteria were commonly found both in species as in the common gut communities of marine fish, whereas Spirochaetes and Tenericutes occupied the flora of A. tetradactylus. We then performed anaerobic and aerobic cultures and isolated 34 and 44 strains including 48 strains belonged to Vibrio species from A. tetradactylus and E. stellifer. We observed that some Vibrio strains formed a clear boundary to avoid contacting other strains of bacteria. Whole-genome sequencing of such two Vibrio alginolyticus strains revealed two cyclic chromosomes commonly found in the genome of Vibrio species, and some unique genes encoding alginate lyase, chitinases, and type I-F CRISPR-associated endoribonuclease for the first time in Vibrio alginolyticus.


Assuntos
Microbioma Gastrointestinal , Perciformes , Vibrio , Animais , Bactérias , Peixes/microbiologia , Vibrio/genética , Vibrio alginolyticus
3.
J Appl Microbiol ; 132(6): 4225-4235, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35332638

RESUMO

AIMS: Develop a species-specific multiplex PCR to correctly identify Edwardsiella species in routine diagnostic for fish bacterial diseases. METHODS AND RESULTS: The genomes of 62 Edwardsiella spp. isolates available from the National Center for Biotechnology Information (NCBI) database were subjected to taxonomic and pan-genomic analyses to identify unique regions that could be exploited by species-specific PCR. The designed primers were tested against isolated Edwardsiella spp. strains, revealing errors in commercial biochemical tests for bacterial classification regarding Edwardsiella species. CONCLUSION: Some of the genomes of Edwardsiella spp. in the NCBI platform were incorrectly classified, which can lead to errors in some research. A functional mPCR was developed to differentiate between phenotypically and genetically ambiguous Edwardsiella, with which, we detected the presence of Edwardsiella anguillarum affecting fish in Brazil. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that the misclassification of Edwardsiella spp in Brazil concealed the presence of E. anguillarum in South America. Also, this review of the taxonomic classification of the Edwardsiella genus is a contribution to the field to help researchers with their sequencing and identification of genomes, showing some misclassifications in online databases that must be corrected, as well as developing an easy assay to characterize Edwardsiella species in an end-point mPCR.


Assuntos
Edwardsiella , Infecções por Enterobacteriaceae , Doenças dos Peixes , Animais , Brasil , Edwardsiella/genética , Edwardsiella tarda/genética , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/diagnóstico , Doenças dos Peixes/microbiologia , Peixes/microbiologia , Reação em Cadeia da Polimerase Multiplex/métodos
4.
Genome Biol Evol ; 14(4)2022 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-35349687

RESUMO

The bioluminescent symbiosis involving the sea urchin cardinalfish Siphamia tubifer and the luminous bacterium Photobacterium mandapamensis is an emerging vertebrate model for the study of microbial symbiosis. However, little genetic data are available for the host, limiting the scope of research that can be implemented with this association. We present a chromosome-level genome assembly for S. tubifer using a combination of PacBio HiFi sequencing and Hi-C technologies. The final assembly was 1.2 Gb distributed on 23 chromosomes and contained 32,365 protein coding genes with a BUSCO score of 99%. A comparison of the S. tubifer genome to that of another nonluminous species of cardinalfish revealed a high degree of synteny, whereas a comparison to a more distant relative in the sister order Gobiiformes revealed the fusion of two chromosomes in the cardinalfish genomes. The complete mitogenome of S. tubifer was also assembled, and an inversion in the vertebrate WANCY tRNA genes as well as heteroplasmy in the length of the control region were discovered. A phylogenetic analysis based on whole the mitochondrial genome indicated that S. tubifer is divergent from the rest of the cardinalfish family, highlighting the potential role of the bioluminescent symbiosis in the initial divergence of Siphamia. This high-quality reference genome will provide novel opportunities for the bioluminescent S. tubifer-P. mandapamensis association to be used as a model for symbiosis research.


Assuntos
Perciformes , Simbiose , Animais , Cromossomos , Peixes/genética , Peixes/microbiologia , Perciformes/genética , Perciformes/microbiologia , Filogenia , Simbiose/genética
5.
Sci Rep ; 12(1): 3003, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35194033

RESUMO

Bacterial kidney disease (BKD) is a chronic bacterial disease affecting both wild and farmed salmonids. The causative agent for BKD is the Gram-positive fish pathogen Renibacterium salmoninarum. As treatment and prevention of BKD have proven to be difficult, it is important to know and identify the key bacterial proteins that interact with the host. We used subcellular fractionation to report semi-quantitative data for the cytosolic, membrane, extracellular, and membrane vesicle (MV) proteome of R. salmoninarum. These data can aid as a backbone for more targeted experiments regarding the development of new drugs for the treatment of BKD. Further analysis was focused on the MV proteome, where both major immunosuppressive proteins P57/Msa and P22 and proteins involved in bacterial adhesion were found in high abundance. Interestingly, the P22 protein was relatively enriched only in the extracellular and MV fraction, implicating that MVs may play a role in host-pathogen interaction. Compared to the other subcellular fractions, the MVs were also relatively enriched in lipoproteins and all four cell wall hydrolases belonging to the New Lipoprotein C/Protein of 60 kDa (NlpC/P60) family were detected, suggesting an involvement in the formation of the MVs.


Assuntos
Vesículas Citoplasmáticas/fisiologia , Proteoma/genética , Proteômica , Virulência , Animais , Aderência Bacteriana/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/fisiologia , Vesículas Citoplasmáticas/metabolismo , Doenças dos Peixes/microbiologia , Peixes/microbiologia , Interações Hospedeiro-Parasita , Nefropatias/microbiologia , Nefropatias/veterinária , Lipoproteínas/metabolismo , Renibacterium/citologia , Renibacterium/genética , Renibacterium/patogenicidade , Frações Subcelulares/fisiologia , Virulência/genética
6.
J Food Prot ; 85(6): 956-960, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35202455

RESUMO

ABSTRACT: Histamine-forming bacteria (HFB) were isolated from the 70 salted fish samples bought from town markets of Guangdong Province of south China. In addition, the histamine-forming ability of HFB was analyzed. There were 31 strains of HFB isolated from 36 salted fish pickled overnight. They were identified as six bacteria species: Vibrio alginolyticus, Vibrio rumoiensis, Staphylococcus saprophyticus, Staphylococcus xylosus, Lactococcus lactis, and Morganella morganii. The rate of confirmation of V. alginolyticus was highest (23 of 31), exceeding 200 mg/kg histamine. In particular, M. morganii produced a histamine amount that exceeded 2,000 mg/kg, although it was only one isolate in this study. In addition, five bacteria species of HFB were isolated from 34 dried salted fish. Among them, S. saprophyticus was dominant in the dried salted fish but produced histamines below 200 mg/kg. However, Enterobacter aerogenes from dried salted fish formed a histamine amount exceeding 200 mg/kg. The study showed that the dominant strain of HFB was different in two kinds of salted fish. Both kinds of salted fish contained HFB whose histamine-forming capacity exceeded 200 mg/kg. As a result, the safety of salted fish should be of concern, especially salted fish pickled overnight.


Assuntos
Histamina , Morganella morganii , Animais , Bactérias , Produtos Pesqueiros/microbiologia , Peixes/microbiologia , Prevalência , Cloreto de Sódio
7.
J Fish Dis ; 45(4): 547-560, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35000204

RESUMO

The freshwater ornamental fish trade represents a major contributor to the livelihoods of many producers in Trinidad and Tobago, with stocks destined for local, regional and international markets. A review of clinical cases presented to the Aquatic Animal Health Unit at the University of the West Indies, School of Veterinary Medicine for the period September 2010 to December 2012 suggested that piscine mycobacteriosis may be widespread throughout the local ornamental fish industry. Thus, to determine the prevalence of mycobacteriosis in ornamental fish sold in pet stores, a total of 122 specimens were sourced from 24 retail suppliers across Trinidad. Fish were killed and internal organs were examined for lesions suggestive of granulomas. All wet-mount slides were acid-fast stained, regardless of the presence or absence of observed granuloma-like lesions. Histological analysis was performed on one randomly selected whole specimen from each facility. Mycobacterium sp. was identified using real-time PCR detecting the 16S rRNA gene in tissue samples. Associations between parasitism, facility biosecurity and presence of positive animals were determined. The prevalence of Mycobacterium sp. infection was 61 ± 7% (74/122), with positive specimens being acquired from 54.2% (13/24) of facilities examined. Further, 100% of facilities did not employ optimum biosecurity measures.


Assuntos
Doenças dos Peixes , Infecções por Mycobacterium , Animais , Doenças dos Peixes/microbiologia , Peixes/microbiologia , Infecções por Mycobacterium/epidemiologia , Infecções por Mycobacterium/microbiologia , Infecções por Mycobacterium/veterinária , RNA Ribossômico 16S/genética , Trinidad e Tobago/epidemiologia
8.
Appl Environ Microbiol ; 88(6): e0241821, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35080904

RESUMO

Fish-pathogenic bacteria of the Tenacibaculum genus are a serious emerging concern in modern aquaculture, causing tenacibaculosis in a broad selection of cultured finfish. Data describing their virulence mechanisms are scarce and few means, antibiotic treatment aside, are available to control their proliferation in aquaculture systems. We genome sequenced a collection of 19 putative Tenacibaculum isolates from outbreaks at two aquaculture facilities and tested their susceptibility to treatment with tropodithietic acid (TDA)-producing Roseobacter group probiotics. We found that local outbreaks of Tenacibaculum can involve heterogeneous assemblages of species and strains with the capacity to produce multiple different virulence factors related to host invasion and infection. The probiotic Phaeobacter piscinae S26 proved efficient in killing pathogenic Tenacibaculum species such as T. maritimum, T. soleae, and some T. discolor strains. However, the T. mesophilum and T. gallaicum species exhibit natural tolerance toward TDA and are hence not likely to be easily killed by TDA-producing probiotics. Tolerance toward TDA in Tenacibaculum is likely involving multiple inherent physiological features pertaining to electron and proton transport, iron sequestration, and potentially also drug efflux mechanisms, since genetic determinants encoding such features were significantly associated with TDA tolerance. Collectively, our results support the use of TDA producers to prevent tenacibaculosis; however, their efficacy is likely limited to some Tenacibaculum species. IMPORTANCE A productive and sustainable aquaculture sector is needed to meet the UN sustainable development goals and supply the growing world population with high-protein food sources. A sustainable way to prevent disease outbreaks in the industry is the application of probiotic bacteria that can antagonize fish pathogens in the aquaculture systems. TDA-producing Roseobacter group probiotics have proven efficient in killing important vibrio pathogens and protecting fish larvae against infection, and yet their efficacy against different fish pathogenic species of the Tenacibaculum genus has not been explored. Therefore, we tested the efficacy of such potential probiotics against a collection of different Tenacibaculum isolates and found the probiotic to efficiently kill a subset of relevant strains and species, supporting their use as sustainable disease control measure in aquaculture.


Assuntos
Doenças dos Peixes , Probióticos , Roseobacter , Tenacibaculum , Animais , Aquicultura , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Peixes/microbiologia , Tenacibaculum/genética
9.
Mar Pollut Bull ; 174: 113188, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34856431

RESUMO

In this study, we reported Shiga toxin-producing Escherichia coli (STEC) in 847 samples, including those in coastal waters, sediments, and fish samples in the Southeast Coast of India. A total of 3742 E. coli strains were identified using conventional and molecular identification methods. Of these, 1518 isolates expressed virulent genes Stx1, Stx2, and Eae; effects on these genes on toxicity were examined. Furthermore, 2224 non-STEC isolates caused hemolytic uremic syndrome and played a key role in the persistence of STEC contamination. We conclude that toxin production is not adequate to cause disease, and the pathogenic mechanism of STEC remains poorly defined. Therefore, the present study indicates the status of pollution, highlighting the need for sanitation in public health.


Assuntos
Proteínas de Escherichia coli , Água do Mar/microbiologia , Escherichia coli Shiga Toxigênica , Animais , Proteínas de Escherichia coli/genética , Peixes/microbiologia , Sedimentos Geológicos/microbiologia , Índia , Toxina Shiga , Toxina Shiga I/genética , Escherichia coli Shiga Toxigênica/isolamento & purificação
10.
Microb Drug Resist ; 28(2): 255-265, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34569863

RESUMO

Vibrio harveyi is a significant cause of infection in both marine animals and humans. It has been reported frequently in seafood-borne infections worldwide. This study was conducted to determine the potential health impact of the V. harveyi isolated from marine food fish cultured in Korea concerning their virulence and antimicrobial resistance. A total of 49 V. harveyi samples were isolated by biochemical tests and multiplex PCR. Phenotypic detection of virulence factors resulted DNase activity (81.63%), hemolysis (α = 75.51% and ß = 12.25), gelatinase activity (71.43%), protease production (71.43%), phospholipase activity (65.31%), and lipase production (34.69%). Virulence genes, including VPI, tlh, tdh, toxR, VAC, and ctxAB, were detected in 57.14%, 44.90%, 36.73%, 22.45%, 12.24%, and 8.16% of the isolates, respectively. Resistance to ampicillin (77.55%), oxacillin (69.39%), nalidixic acid (53.06%), amoxicillin (46.94%), oxytetracycline (46.94%), colistin sulfate (34.69%), fosfomycin (34.69%), chloramphenicol (32.65%), streptomycin (32.65%), cephalothin (28.57%), oxytetracycline (26.53%), ceftriaxone (20.41%), erythromycin (14.29%), and cefoxitin (12.24%) was detected in disc diffusion assay. Most of the isolates were classified as multidrug resistant as they scored multiple antimicrobial resistance index ≥0.2. Furthermore, antimicrobial resistance genes tetB, qnrA, intI1 (Class 1 integron integrase), aac(6')-Ib, blaSHV, blaCTX-M, strA-strB, tetA, aphAI-IAB, qnrC, qnrS, and blaTEM were found in 81.63%, 67.35%, 61.22%, 46.94%, 44.90%, 44.90%, 36.73%, 18.37%, 10.20%, 10.20%, 8.16% and 6.12% of the isolates, respectively. In conclusion, the development of antimicrobial resistance among V. harveyi will ultimately reduce the efficacy of antimicrobials used for treating and can favor the development of more virulent V. harveyi strains.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Peixes/microbiologia , Genes Bacterianos/genética , Alimentos Marinhos/microbiologia , Vibrio/genética , Animais , Pesqueiros , Testes de Sensibilidade Microbiana , Fenótipo , República da Coreia , Vibrio/efeitos dos fármacos , Virulência/genética
11.
J Anim Physiol Anim Nutr (Berl) ; 106(2): 441-469, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34355428

RESUMO

The microbiome actually deals with micro-organisms that are associated with indigenous body parts and the entire gut system in all animals, including human beings. These microbes are linked with roles involving hereditary traits, defence against diseases and strengthening overall immunity, which determines the health status of an organism. Considerable efforts have been made to find out the microbiome diversity and their taxonomic identification in finfish and shellfish and its importance has been correlated with various physiological functions and activities. In recent past due to the availability of advanced molecular tools, some efforts have also been made on DNA sequencing of these microbes to understand the environmental impact and other stress factors on their genomic structural profile. There are reports on the use of next-generation sequencing (NGS) technology, including amplicon and shot-gun approaches, and associated bioinformatics tools to count and classify commensal microbiome at the species level. The microbiome present in the whole body, particularly in the gut systems of finfish and shellfish, not only contributes to digestion but also has an impact on nutrition, growth, reproduction, immune system and vulnerability of the host fish to diseases. Therefore, the study of such microbial communities is highly relevant for the development of new and innovative bio-products which will be a vital source to build bio and pharmaceutical industries, including aquaculture. In recent years, attempts have been made to discover the chemical ingredients present in these microbes in the form of biomolecules/bioactive compounds with their functions and usefulness for various health benefits, particularly for the treatment of different types of disorders in animals. Therefore, it has been speculated that microbiomes hold great promise not only as a cure for ailments but also as a preventive measure for the number of infectious diseases. This kind of exploration of new breeds of microbes with their miraculous ingredients will definitely help to accelerate the development of the drugs, pharmaceutical and other biological related industries. Probiotic research and bioinformatics skills will further escalate these opportunities in the sector. In the present review, efforts have been made to collect comprehensive information on the finfish and shellfish microbiome, their diversity and functional properties, relationship with diseases, health status, data on species-specific metagenomics, probiotic research and bioinformatics skills. Further, emphasis has also been made to carry out microbiome research on priority basis not only to keep healthy environment of the fish farming sector but also for the sustainable growth of biological related industries, including aquaculture.


Assuntos
Peixes , Microbioma Gastrointestinal , Frutos do Mar , Animais , Aquicultura , Peixes/microbiologia , Frutos do Mar/microbiologia
12.
Fish Shellfish Immunol ; 121: 404-417, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34971737

RESUMO

Sturgeons are chondrostean fish critically endangered due to anthropogenic loss and degradation of natural habitat and overfishing for meat and caviar production. Consequently, sturgeon aquaculture has extensively developed lately, being Russian sturgeon (Acipenser gueldenstaedtii) the second most important species reared for caviar production. However, Russian sturgeon aquaculture in subtropical countries, such as Uruguay, confronts difficulties because fish have to endure excessive summertime warm temperatures, which weaken their innate defences facilitating opportunistic infections. To address this problem, we look for identifying putative acute phase proteins (APPs), which might be robust serum biomarkers of both infection and chronic thermal stress, applied to monitoring Russian sturgeon health status in farms. We focused on the C-Reactive Protein/Serum Amyloid P (CRP/SAP) pentraxin since the pentraxin family includes well-known APPs, better characterised in mammals than fish. We identified A.gueldenstaedtii CRP/SAP (AgCRP/SAP), as a member of the universal CRP/SAP pentraxin sub-family, and studied AgCRP/SAP involvement in sturgeon response to bacterial challenge and chronic thermal stress, in comparison with A. gueldenstaedtii Serum Amyloid A (AgSAA), a previously described positive APP. Results showed that AgCRP/SAP is a constitutive serum component that remained constant upon Aeromonas hydrophila challenge and chronic thermal stress. Contrastingly, serum AgSAA was subjected to regulation by bacterial and thermal stress challenges, showing a 50-fold increase and 3-fold decline in serum levels, respectively. Overall, results highlight the potential value of AgSAA, but not of AgCRP/SAP, as a biomarker of bacterial infection and the need to continue searching for robust chronic thermal stress biomarkers in sturgeons.


Assuntos
Infecções Bacterianas/veterinária , Peixes , Resposta ao Choque Térmico , Imunidade Inata , Proteínas de Fase Aguda , Animais , Infecções Bacterianas/imunologia , Proteína C-Reativa , Peixes/imunologia , Peixes/microbiologia , Sistema Imunitário , Proteína Amiloide A Sérica , Componente Amiloide P Sérico
13.
Sci Rep ; 11(1): 23497, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34873246

RESUMO

Selection for bacteria which are K-strategists instead of r-strategists has been shown to improve fish health and survival in aquaculture. We considered an experiment where microcosms were inoculated with natural seawater and the selection regime was switched from K-selection (by continuous feeding) to r-selection (by pulse feeding) and vice versa. We found the networks of significant co-occurrences to contain clusters of taxonomically related bacteria having positive associations. Comparing this with the time dynamics, we found that the clusters most likely were results of similar niche preferences of the involved bacteria. In particular, the distinction between r- or K-strategists was evident. Each selection regime seemed to give rise to a specific pattern, to which the community converges regardless of its prehistory. Furthermore, the results proved robust to parameter choices in the analysis, such as the filtering threshold, level of random noise, replacing absolute abundances with relative abundances, and the choice of similarity measure. Even though our data and approaches cannot directly predict ecological interactions, our approach provides insights on how the selection regime affects the composition of the microbial community, providing a basis for aquaculture experiments targeted at eliminating opportunistic fish pathogens.


Assuntos
Estruturas Bacterianas/fisiologia , Microbiota/fisiologia , Animais , Aquicultura/métodos , Bactérias , Peixes/microbiologia , Água do Mar/microbiologia
14.
Microb Genom ; 7(12)2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34895403

RESUMO

Group B Streptococcus (GBS; Streptococcus agalactiae) is the most common cause of neonatal meningitis and a rising cause of sepsis in adults. Recently, it has also been shown to cause foodborne disease. As with many other bacteria, the polysaccharide capsule of GBS is antigenic, enabling its use for strain serotyping. Recent advances in DNA sequencing have made sequence-based typing attractive (as has been implemented for several other bacteria, including Escherichia coli, Klebsiella pneumoniae species complex, Streptococcus pyogenes, and others). For GBS, existing WGS-based serotyping systems do not provide complete coverage of all known GBS serotypes (specifically including subtypes of serotype III), and none are simultaneously compatible with the two most common data types, raw short reads and assembled sequences. Here, we create a serotyping database (GBS-SBG, GBS Serotyping by Genome Sequencing), with associated scripts and running instructions, that can be used to call all currently described GBS serotypes, including subtypes of serotype III, using both direct short-read- and assembly-based typing. We achieved higher concordance using GBS-SBG on a previously reported data set of 790 strains. We further validated GBS-SBG on a new set of 572 strains, achieving 99.8% concordance with PCR-based molecular serotyping using either short-read- or assembly-based typing. The GBS-SBG package is publicly available and will hopefully accelerate and simplify serotyping by sequencing for GBS.


Assuntos
Peixes/microbiologia , Doenças Transmitidas por Alimentos/microbiologia , Streptococcus agalactiae/classificação , Sequenciamento Completo do Genoma/métodos , Animais , Bases de Dados Genéticas , Tamanho do Genoma , Genoma Bacteriano , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Filogenia , Sorotipagem , Streptococcus agalactiae/genética , Streptococcus agalactiae/isolamento & purificação
15.
Vet Res ; 52(1): 146, 2021 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-34924019

RESUMO

Gram-negative bacteria are known to subvert eukaryotic cell physiological mechanisms using a wide array of virulence factors, among which the type three-secretion system (T3SS) is often one of the most important. The T3SS constitutes a needle-like apparatus that the bacterium uses to inject a diverse set of effector proteins directly into the cytoplasm of the host cells where they can hamper the host cellular machinery for a variety of purposes. While the structure of the T3SS is somewhat conserved and well described, effector proteins are much more diverse and specific for each pathogen. The T3SS can remodel the cytoskeleton integrity to promote intracellular invasion, as well as silence specific eukaryotic cell signals, notably to hinder or elude the immune response and cause apoptosis. This is also the case in aquatic bacterial pathogens where the T3SS can often play a central role in the establishment of disease, although it remains understudied in several species of important fish pathogens, notably in Yersinia ruckeri. In the present review, we summarise what is known of the T3SS, with a special focus on aquatic pathogens and suggest some possible avenues for research including the potential to target the T3SS for the development of new anti-virulence drugs.


Assuntos
Organismos Aquáticos , Proteínas da Membrana Bacteriana Externa , Fenômenos Fisiológicos Bacterianos , Sistemas de Secreção Tipo III , Animais , Organismos Aquáticos/fisiologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Doenças dos Peixes/microbiologia , Peixes/microbiologia , Dor/veterinária , Transporte Proteico , Sistemas de Secreção Tipo III/metabolismo , Fatores de Virulência/metabolismo
16.
Biomed Res Int ; 2021: 7190152, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34950735

RESUMO

Bacteriocin-like inhibitory substances (BLIS) have sparked great interest because of their promising use in food as natural antimicrobial agents. In this work, six Streptomyces isolates obtained from the gut of Chanos chanos demonstrated their ability to produce extracellular metabolites with inhibitory activity against Salmonella enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus. Exposure of the extracellular metabolites to proteolytic enzymes (i.e., proteinase-K, trypsin, and pepsin) revealed high sensitivity and confirmed their proteinaceous nature. The metabolites were stable at high temperatures (up to 100°C for 30 min) and a wide range of pH (pH 2.0-7.0). Fractionation of the crude BLIS by filtration yielded three fractions based on molecular weight: <3 kDa, 3-10 kDa, and >10 kDa. Analysis of the antibacterial activity of these fractions showed increased specific activity, especially in the fraction with a molecular weight (MW) of <3 kDa, relative to the crude sample. The fraction with MW < 3 kDa had minimum inhibitory and bactericidal concentrations in ranges 0.04-0.62 mg·mL-1 and 0.08-1.25 mg·mL-1, respectively. This fraction also showed better temperature and pH stability compared with crude BLIS. Brine shrimp toxicity assay revealed that this fraction has moderate toxicity with a 50% lethal concentration of 226.975 µg·mL-1 (i.e., moderate toxicity) to Artemia salina. Identification of the peptide sequences of this fraction by liquid chromatography-tandem mass spectrometry yielded 130 proteins with retention times of 15.21-19.57 min. Eleven proteins with MWs of 1345.66-2908.35 Da and composed of less than 30 amino acid residues with high hydrophobicity (15.34-26.22 kcal·mol-1) appeared to be responsible for the antibacterial activity of the fraction. This study revealed the potential application of BLIS from Streptomyces, especially BLIS SCA-8, as antibacterial agents.


Assuntos
Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Peixes/microbiologia , Trato Gastrointestinal/microbiologia , Streptomyces/metabolismo , Animais , Bactérias/efeitos dos fármacos , Microbiologia de Alimentos/métodos
17.
Fish Physiol Biochem ; 47(6): 2041-2053, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34750711

RESUMO

Intestinal flora is closely related to the health of organisms and the occurrence and development of diseases. The study of intestinal flora will provide a reference for the research and treatment of disease pathogenesis. Upon hatching, fish begin to acquire a microbial community in the intestine. In response to the environment and the host itself, the fish gut eventually develops a unique set of microflora, with some microorganisms being common to different fish. The existence of intestinal microorganisms creates an excellent microecological environment for the host, while the fish symbiotically provides conditions for the growth and reproduction of intestinal microflora. The intestinal flora and the host are interdependent and mutually restrictive. This review mainly describes the formation of fish intestinal flora, the function of normal intestinal flora, factors affecting intestinal flora, and a series of fish models.


Assuntos
Peixes/microbiologia , Microbioma Gastrointestinal , Animais , Intestinos/microbiologia
18.
PLoS One ; 16(11): e0260192, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34793569

RESUMO

In this study, we determined the effects of dietary chitosan on the growth, biochemical composition, gut microbiota, and hematological and histological parameters of juvenile Barbonymus gonionotus. Three test diets containing three different concentrations (1, 2, and 3 g kg-1 feed) of dietary chitosan were formulated. A basal diet without dietary chitosan was considered a control, and the fish were reared for 60 days. Comparing the effects of the dietary chitosan-containing diets with those of the control diet, we found that dietary chitosan significantly improved the muscle growth, nutrient and mineral contents, hematological parameters, lactic acid bacterium abundance, and digestive enzyme activities of B. gonionotus. Moreover, dietary chitosan significantly inhibited the growth of pathogenic bacteria in fish. Interestingly, an increase in the dietary chitosan level significantly enhanced the protein contents of the muscles and inversely significantly decreased the lipid contents compared to those with the basal diet. Quantitative study revealed that dietary chitosan significantly enhanced the length of intestinal villi, and qualitative study showed that dietary chitosan considerably reduced the fat content in the liver and improved the morphology of the kidney compared to those with the basal diet. Taken together, our results suggest that the application of dietary chitosan at a dose of 1 g kg-1 feed produced the highest benefit to treated B. gonionotus, indicating its potential for safe use in aquaculture.


Assuntos
Quitosana/administração & dosagem , Peixes/crescimento & desenvolvimento , Peixes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Animais , Dieta , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Intestinos/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Músculos/efeitos dos fármacos , Músculos/metabolismo , Nutrientes/administração & dosagem
19.
Emerg Microbes Infect ; 10(1): 2128-2140, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34702148

RESUMO

Vibrio vulnificus is a pathogen of public health concern that causes either primary septicemia after ingestion of raw shellfish or secondary septicemia after wound exposure to seawater. In consequence, shellfish and seawater are considered its main reservoirs. However, there is one aspect of its biology that is systematically overlooked: its association with fish in its natural environment. This association led in 1975 to the emergence of a zoonotic clade within phylogenetic lineage 2 following successive outbreaks of vibriosis in farmed eels. Although this clade is now worldwide distributed, no new zoonotic clades were subsequently reported. In this work, we have performed phylogenetic, genomic and functional studies to show that other zoonotic clades are in fact present in 4 of the 5 lineages of the species. Further, we associate these clades, most of them previously but incompletely described, with the acquisition of a family of fish virulence plasmids containing genes essential for resistance to the immune system of certain teleosts of interest in aquaculture. Consequently, our results provide several pieces of evidence about the importance of this species as a zoonotic agent linked to fish farms, as well as on the relevance of these artificial environments acting as drivers that accelerate the evolution of the species.


Assuntos
Zoonoses Bacterianas/microbiologia , Doenças dos Peixes/microbiologia , Plasmídeos/genética , Vibrioses/microbiologia , Vibrioses/veterinária , Vibrio vulnificus/genética , Vibrio vulnificus/patogenicidade , Animais , Aquicultura , Zoonoses Bacterianas/transmissão , Peixes/crescimento & desenvolvimento , Peixes/microbiologia , Humanos , Filogenia , Plasmídeos/metabolismo , Vibrioses/transmissão , Vibrio vulnificus/classificação , Vibrio vulnificus/metabolismo , Virulência
20.
J Mol Biol ; 433(24): 167321, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34687715

RESUMO

Obligate symbionts typically exhibit high evolutionary rates. Consequently, their proteins may differ considerably from their modern and ancestral homologs in terms of both sequence and properties, thus providing excellent models to study protein evolution. Also, obligate symbionts are challenging to culture in the lab and proteins from uncultured organisms must be produced in heterologous hosts using recombinant DNA technology. Obligate symbionts thus replicate a fundamental scenario of metagenomics studies aimed at the functional characterization and biotechnological exploitation of proteins from the bacteria in soil. Here, we use the thioredoxin from Candidatus Photodesmus katoptron, an uncultured symbiont of flashlight fish, to explore evolutionary and engineering aspects of protein folding in heterologous hosts. The symbiont protein is a standard thioredoxin in terms of 3D-structure, stability and redox activity. However, its folding outside the original host is severely impaired, as shown by a very slow refolding in vitro and an inefficient expression in E. coli that leads mostly to insoluble protein. By contrast, resurrected Precambrian thioredoxins express efficiently in E. coli, plausibly reflecting an ancient adaptation to unassisted folding. We have used a statistical-mechanical model of the folding landscape to guide back-to-ancestor engineering of the symbiont protein. Remarkably, we find that the efficiency of heterologous expression correlates with the in vitro (i.e., unassisted) folding rate and that the ancestral expression efficiency can be achieved with only 1-2 back-to-ancestor replacements. These results demonstrate a minimal-perturbation, sequence-engineering approach to rescue inefficient heterologous expression which may potentially be useful in metagenomics efforts targeting recent adaptations.


Assuntos
Proteínas de Bactérias/biossíntese , Peixes/microbiologia , Dobramento de Proteína , Proteínas Recombinantes/biossíntese , Vibrionaceae/metabolismo , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Escherichia coli/metabolismo , Metagenômica , Engenharia de Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Simbiose , Tiorredoxinas/biossíntese , Tiorredoxinas/química , Vibrionaceae/genética
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